West Nile Virus Activity Reported in Central Illinois

Mosquitoes testing positive for the West Nile Virus have been detected in Macon County.

What is the significance of West Nile virus?

West Nile virus (WNV) is the leading cause of mosquito-borne disease in the continental United States. Mosquitoes contract the disease from infected birds, then pass it on to other birds, animals, and humans.

What evidence indicates that West Nile virus is active in Central Illinois?

During an August 9th broadcast, WAND-TV news reported that the Macon Mosquito Abatement District (MMAD) detected the first batch of WNV-positive mosquitoes in Macon County.

Why would West Nile virus activity increase in August?

WNV activity is influenced by temperatures, precipitation, relative humidity, and wind. In hot, dry weather, mosquitoes that carry WNV multiply rapidly in stagnant water (i.e., ditches, birdbaths, flowerpots, buckets, etc.).

As of August 17, 2022, only two counties in Illinois have reported WNV-positive bird cases, with eight counties reporting mosquitoes testing positive. According to the Illinois Department of Public Health (IDPH), no human cases of WNV have been reported statewide.

When WNV mosquitoes increase, so does the risk of WNV transmission to birds, pets, livestock (particularly horses), and humans. Therefore, the Moultrie County Health Department encourages all individuals in Central Illinois to reduce their risk of mosquito bites.

What are the symptoms of West Nile virus?

Approximately 80 percent of persons bitten by an infected mosquito have no disease symptoms. The remaining 20% could experience a wide range of symptoms.

Once an individual has been bitten by a mosquito infected with WNV, symptoms usually begin within 3-14 days. In humans, mild cases of WNV infection may cause a slight fever or headache.

However, individuals suffering from more severe WNV infection may experience prolonged fever, head and body aches, disorientation, and convulsions. The most severe WNV infections in humans can result in meningitis, paralysis, and death.

Individuals with chronic health conditions, as well as those 60 years and older, are at greater risk for more severe illness.

You should seek medical attention if you have experienced a mosquito bite and develop any of the above symptoms. While most individuals recover from WNV without difficulty, those experiencing more severe illnesses may need medical intervention.

How can we protect ourselves from West Nile virus?

The first step in protecting yourself from WNV infection is to reduce your risk of exposure to WNV and other mosquito-borne illnesses.

The Centers for Disease Control and Prevention (CDC) recommends reducing the number of mosquitoes around your home and neighborhood by eliminating standing water where mosquitoes can lay eggs. The following will help you accomplish this goal:

1. Once a week, empty and scrub, turn over, cover, or throw out any items that hold water like tires, buckets, planters, toys, pools, birdbaths, flowerpot saucers, or trash containers. Mosquitoes lay eggs near water.
2. Tightly cover water storage containers (buckets, cisterns, rain barrels) so mosquitoes cannot get inside to lay eggs.
3. For containers without lids, use wire mesh with holes smaller than an adult mosquito.
4. Use larvicides to treat large containers of water that will not be used for drinking and cannot be covered or dumped out.
5. If you have a septic tank, repair cracks or gaps. Cover open vent or plumbing pipes. Use wire mesh with holes smaller than an adult mosquito.

The CDC also urges you to take personal precautions to avoid mosquito bites. Again, the best “protection” is to reduce your risk of exposure. Avoid being outdoors when mosquitoes are most active during dawn and dusk. Additionally, use EPA-registered insect repellant containing DEET and apply it when outside.

Finally, wearing long-sleeved shirts and long pants also protects vulnerable skin from mosquito bites. This added “layer” of protection is especially helpful if you cannot avoid areas or times where mosquito activity is high.

Where can I find additional information about West Nile virus and its prevention?

More information about WNV, other mosquito-borne illnesses, and prevention is available through the IDPH, the CDC, or by contacting the Moultrie County Health Department at 217-728-4114.